This invention relates generally to vehicle vibration diagnostics. In particular, the invention relates to a system and method for measuring and evaluating torsional vibration in a vehicle.
Torsional vibration problems are a significant source of premature component failure and noise, in devices such as vehicles and industrial equipment (collectively xe2x80x9cvehiclesxe2x80x9d). Instead of investigating the potentially ongoing root cause of a damaged component, damaged components are frequently replaced without any investigation of the underlying cause of the damage. Without addressing the root causes of the problem, the same problem often repeats itself, requiring the subsequent replacement of future damaged components. Such a practice can be very time consuming and expensive.
To combat the xe2x80x9ctrial and errorxe2x80x9d prior art approach, U.S. Pat. No. 6,128,959 (Patent ""959) discloses a driveline vibration analyzer for measuring, analyzing, and characterizing the torsional vibrations in a vehicle driveline. The driveline vibration analyzer in Patent ""959 discloses the use of a vibration analyzer with a single sensor and a single input channel.
There are instances when it would be desirable for a vibration analyzer to receive sensor measurements from multiple sensors and multiple input channels. The most important vehicle location from a vibration analysis perspective may vary from vehicle to vehicle, and from situation to situation. In varying vehicle environments, different locations in the vehicle will be of greater interest with respect to torsional vibration. Thus, it would be desirable for vibration analyzers to utilize multiple sensors at different locations in the vehicle to monitor multiple locations in the vehicle without the need to attempt to replicate test conditions or conduct duplicative tests.
The counter-timers used by Patent ""959 typically utilize teeth flywheels that measure time in terms of the number of clicks, not the passage of time per se. Thus, the use of multiple sensor in a simultaneous or substantially simultaneous manner requires the integration of sensor measurements from sensor recording data at different rates and time intervals. It would be desirable for a multi-channel vibration analyzer to be able to read sensor measurements using sensor that operate at different rates and over different time intervals. It would also be desirable for a multi-channel vibration analyzer to be flexible in terms of sensor locations so that different components in the vehicle can be isolated and tested with respect to torsional vibration, without the unwanted complexity and likely errors associated with replicating test conditions or conducting duplicative tests.
Vibration analysis is subject to potentially many different variables that depend on the particular environment of the vehicle and the sensor used to evaluate vibration in the vehicle. It would be desirable for a multi-channel vibration analyzer to be flexible in the different types of environment-specific parameters that can be incorporated into the setup of the analyzer, the measurements sent to the analyzer, and the subsequent analysis of those measurements.
The multi-channel vibration analyzer (xe2x80x9cvibration analyzerxe2x80x9d) of the present invention uses sensor at different locations in a vehicle to capture various sensor measurements. These sensor measurements can be used by the vibration analyzer to generate vibration characteristics useful in analyzing the torsional vibration at various locations in the vehicle. The vibration analyzer can incorporate different sensor measurements in a simultaneous or substantially simultaneous manner, even though the sensor may collect data at different rates and over different time intervals.
The vibration analyzer can incorporate three distinct subsystems to facilitate the flexibility of the vibration analyzer with respect to user requirements and particular vehicle environments. A setup subsystem can be used to select sensor locations. Sensor locations can be selected from a predefined list of useful sensor locations, or the user can use the setup subsystem to define new sensor locations and new combinations of sensor locations. The setup subsystem be used to define any vehicle-specific or environment-specific variables that should be incorporated into a vibration analysis. The vibration analyzer can also include an acquisition subsystem for capturing sensor measurements. Sensor measurements can be saved on a memory component of the vibration analyzer to allow the re-use of the same data for analysis purposes. An analysis subsystem can generate a vibration analysis from the sensor measurements captured by the acquisition subsystem and the setup attributes of the setup subsystem.
The system can provide a flexible means for incorporating sensor measurements from multiple sensor readings, and integrating those sensor readings with one or more setup attributes, to generate one or more vibration attributes useful in describing the vibration characteristics of the vehicle.